Finding the Fourth Proportional to 1,658.55, 2,487.69 and 780.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,658.55 : 2,487.69 = 780.84 : x
2. Step 2: Convert to fraction form
   1,658.55/2,487.69 = 780.84/x
3. Step 3: Cross multiply
   1,658.55x = 2,487.69 × 780.84
4. Step 4: Simplify right side
   1,658.55x = 1,942,487.86
5. Step 5: Solve for x
   x = 1,942,487.86/1,658.55
6. Step 6: Final answer
   x = 1,171.20